North Downs Line

Between Redhill and Ash the line runs roughly parallel with the North Downs. Between Reigate and Gomshall the line runs along the foot of the North Downs escarpment in the Vale of Holmesdale. At Guildford it passes through the gap in the Downs formed by the River Wey, with a short tunnel just south of Guildford station, and further west between Guildford and Ash the line runs to the north of the Hog's Back. It then follows the Blackwater valley as far as Sandhurst, before continuing to Reading.

The line was authorised by Acts of Parliament in 1846 and 1847 and most of it was constructed by the Reading, Guildford and Reigate Railway Company (RG&RRC), opening in 1849. (A central section of the line near Guildford was built by a predecessor of the LSWR.) The stated objective of the company was to

"secure through traffic passing between the West, North and Midlands and the Channel Ports avoiding the congestion of London and thus saving time, distance and expense."[1]

Although the company had some independent shareholders, it was closely associated with the South Eastern Railway (SER). The original intention was for the SER to build part of the line itself, but this proposal was rejected by Parliament. The independence of the company was only a formality to satisfy Parliament. The two companies had some common directors; an SER engineer controlled the construction of the line. As intended at outset, the line was leased to the SER in 1850, and the two companies finally merged in 1852. The company's relationship with the GWR is described as "enigmatic". The GWR initially offered the company the use of its facilities at Reading station but terms could not be agreed and a separate station was built.[2]

The SER operated the line from its opening, and ran passenger services on it from Reading to London Charing Cross via Redhill. Even today, the distances along the line between Redhill (22 miles 40 chains) and Shalford Junction (41 mi 60 ch), and between Ash Junction (48 mi 34 ch) and Reading (68 mi 68 ch) are measured from the Charing Cross terminus of the former SER.[3]

North Downs Line
Great Western main line Reading Reading Southern River Kennet Earley River Loddon Winnersh Triangle Winnersh M4 motorway Wokingham B3349 road Waterloo–Reading line Crowthorne Sandhurst Blackwater M3 motorway Farnborough North South Western main line North Camp LC North Camp Alton line Basingstoke Canal Aldershot Farnham Junction │ Ash Tongham │ A323 road Ash Green Halt Ash Junction closed December 1960 Wanborough Portsmouth Direct line New Guildford line Guildford Chalk Tunnel St Catherine's (Sand) Tunnel Portsmouth Direct line River Wey Shalford A248 road Chilworth LC Chilworth Brook LC Burrows Lane LC River Tillingbourne Gomshall Westcott Range Halt Dorking West Dorking Deepdene Sutton and Mole Valley lines Dorking link closed 1946 River Mole Brockham LC Betchworth Quarry Betchworth B2032 road Buckland LC A217 road Reigate Redhill Brighton main line Redhill–Tonbridge line

The line is two-track throughout and is designated W6 loading gauge. Overnight engineering possessions of up to ​4 ¹⁄₂ hours are available.[4]

• Reading to Wokingham is electrified (3rd rail, 750 V DC) and signalled under the track circuit block system from Wokingham Signal Box. Signalling headways are 3 minutes for fast services and ​3 ¹⁄₂ minutes for stopping services. The line speed is 70 mph (110 km/h), except for two 30 mph (48 km/h) restrictions (on the approach to Reading and through Wokingham station).
• Wokingham to North Camp is also under the control of Wokingham Signal Box, although long distances between signals increase headways to 6 minutes and 11 minutes for fast and stopping services respectively (the longest headways on the line). This section is not electrified and the line speed is 70 mph. It is currently planned to transfer the control of Wokingham Signal Box to the new Rail Operating Centre in Basingstoke in 2017/18.
• North Camp to Shalford Junction is controlled from Guildford (TCB). Signalling headways are 2 minutes for fast services and 3 minutes for stopping services. This section is electrified (3rd rail, 750 V DC) from Aldershot South Junction. The line speed is 70 mph, except for a 40 mph (64 km/h) restriction at Ash Junction (between Ash and Wanborough) where the line curves sharply, and a 30 mph restriction on the approaches to Guildford station. Resignalling in October 1999 enabled reversible working on the down line through both tunnels between Guildford and Shalford Junction.[4]
• Shalford Junction to Reigate The route leaves the Portsmouth Direct Line at Shalford Junction and there is a 20 mph restriction. From here to Reigate, the line is not electrified. It is controlled by Guildford from Shalford Junction to Gomshall and by Reigate Signal Box (TCB) from Gomshall to Redhill. Signalling headways are 5 minutes for fast trains and 7 minutes for stopping services. The line speed varies from 30 mph (on the approach to Shalford junction) to 70 mph.
• Redhill to Reigate is electrified (3rd rail, 750 V DC). The approach to Redhill is controlled by Three Bridges Signalling Centre and has a 30 mph speed restriction.

The major capacity constraints are the platform capacities of Reading, Redhill and Gatwick Airport stations.[5][6][7]

At Reading, North Downs Line services normally terminate at platforms 4, 5 and 6 on the south side of the station, although access to other platforms is possible via Reading Spur Junction with the Great Western Main Line (see map, right). Trains may access the north side of Reading station via a single track underpass. Previously, the access to platforms 4 and 5 (formerly 4a and 4b) was via a short single track section, which severely limited capacity. As part of the 2012 Reading resignalling scheme, an additional platform has been provided for North Downs Line services; platforms have consequentially been re-numbered as 4 (former 4a), 5 (former 4b) and 6 (new).[8]

Capacity restraints at Redhill were also improved by the creation of a new platform and improvements to track work south of the station, as part of the Solum Regeneration project.[9] A new platform at Gatwick Airport was officially opened in February 2014. The new platform at Redhill opened in 2019 from which time additional services were planned to travel through to Gatwick Airport.[10]

Network SouthEast originally planned to electrify the whole route, with a completion date of 1993 being published, but these plans were dropped.[11]

First Great Western Class 165 at Guildford station

The main services on the line are provided by Great Western Railway using Class 165 and Class 166 Network Turbo diesel multiple units. Hourly semi-fast services run from Reading to Gatwick Airport and there is an hourly stopping service between Reading and Redhill. At Redhill the Gatwick Airport services reverse to head south along the Brighton Main Line.[5] Until 1994, the stopping services continued to Tonbridge, but the line between Redhill and Tonbridge was electrified in 1993 to provide an additional diversionary route for Eurostar trains to continental Europe. Tains on this section are now operated (by Southern) as a shuttle service between Redhill and Tonbridge only.[12]

In 2020 the Class 165 trains are due to be replaced by Class 769 Flex four-carriage trains, once a number of station platforms have been extended.[13]

Additional services on the North Downs Line are provided by South Western Railway between Reading and Wokingham (trains to/from London Waterloo) and between Ash and Guildford (trains to/from Alton or Ascot). Southern operates services between Reigate and Redhill and onwards to London.[12]

There is also one train a day in each direction between Reading and Guildford, operated by CrossCountry. These trains run to and from Newcastle.

Class 206 3R unit at Guildford station, June 1979

Steam traction was replaced by 3R (Class 206) DEMUs on 4 January 1965. The new trains consisted of two 6S (class 201) coaches from the Hastings Line coupled to adapted 2EPB driving trailer units. As a result of the visible difference in width between the narrow Hastings Line stock and the standard width Hampshire trailer, the units were nicknamed Tadpoles.[14] Additional peak time services were hauled by class 33 diesel locomotives until May 1977.[1]
The express service from Reading to Gatwick Airport was launched on 12 May 1980, using three-car class 119 DMUs, based on the Western Region. The trains were especially modified for this service, to create extra luggage space: the buffet counter in the centre coach being removed. Class 101 three-car units were later used on the route as well.[15]
All of the stations between Shalford and Betchworth inclusive, were recommended for closure in the 1963 Reshaping of British Railways report.[16] The report recommended that the whole of the North Downs Line should be developed as a trunk route.[17]

As of 2007 no scheduled freight services used the line.[5] The Travelling Post Office train from Dover to Manchester Piccadilly via Tonbridge, Redhill, Guildford and Reading was routed along the line from May 1988 until 2004.[1] The Network Rail 2008 Strategic Business Plan recommended that an enhancement project for the line should be pursued to enable freight traffic from the Channel Tunnel to use the line.[18]

Wanborough railway station

Electrification had been shelved prior to World War II as it was felt that little traffic would be generated. Non-electrified parts of the North Downs Line included Wokingham to Ash (Aldershot South Junction) and Shalford Junction to Reigate. In August 1981 Modern Railways magazine studied an electrification strategy for the then Southern Region of British Railways. The article saw potential on the route with the area having developed rapidly, and also with the prospect of Channel Tunnel traffic; cross-country passenger and freight workings might also be diverted along the route. Subsequently, some of the routes considered were electrified, including South Croydon – Oxted – East Grinstead (1987) Bournemouth – Weymouth (1988), Hilsea and Farlington Junction – St Denys and Eastleigh (1990) and Redhill – Tonbridge (1994). Until then, North Downs Line services continued from Redhill to Tonbridge.

Hurst Green and Tunbridge Wells to Eridge and Uckfield were also included in the same proposals, but were ultimately not electrified. The Tunbridge Wells – Eridge route closed to BR passenger traffic in 1985, and the line to Uckfield remains unelectrified to this day.

According to internet sources, electrification of these sections of the North Downs Line was again discussed as part of the Blackwater Valley Rail Survey, in 1991. Motive power from the outset would have been the BR Mark I-based electric stock classes, but the idea was set aside, when the existing diesel multiple units on the region began to be replaced by the current Class 165/166 'Turbos'.

After the privatisation of British Rail, Railtrack electrified a siding on the line at Wokingham.

Electrification was proposed again in 2016 by Surrey County Council, based on research by four local enterprise partnerships. It was "suggested that the electrification would create around 8,000 jobs and stimulate £1.9 billion of economic growth".[19][20]

Chilworth Railway Station

On the south side of the line between Chilworth and Gomshall, a box hedge topiary known as Jessie's Seat has been cut in the shape of a pheasant, perched on the back of a seat. It is a memorial to South Eastern Railway's guard Henry Wicks who was killed in an accident here in 1892.[21]

Wikimedia Commons has media related to North Downs Line.

• Great Western Main Line
• Waterloo–Reading line
• Alton Line
• Portsmouth Direct Line
• Mole Valley line
• Brighton Main Line
• Redhill–Tonbridge line

• Brown, David; Jackson, Alan A. (1990). Network SouthEast Handbook. Harrow Weald: Capital Transport Publishing. ISBN 1-85414-129-5.CS1 maint: ref=harv (link)
• Butt, R.V.J. (1995). The Directory of Railway Stations. Patrick Stephens Ltd. ISBN 1-85260-508-1.
• Jackson, A.A. (1988). Dorking's Railways. Dorking: Dorking Local History Group. ISBN 1-870912-01-2.CS1 maint: ref=harv (link)